Annealing oven



L. D. KAY

ANNEALING OVEN Nov. 13, 1962 4 Sheets-Sheet 1 Z/oya D. K ay,

INVENTOR.

Filed Oct. 12. 1960 Mom L. D. KAY

ANNEALING OVEN Nov. 13, 1962 4 Sheets-Sheet 3 Filed Oct. 12, 1960 1952 D. KAY 3,063,693

ANNEALING OVEN Filed Oct. 12, 1960 4 SheetsSheet 4 Z/oya 0. A2,,

INVENTOR.

4/10 may United States Patent Gfifice 3,053,693 Patented Nov. 13, 1962 3,063,693 ANNEALEJG OVEN Lloyd 1). Kay, San Marino, Calif., assignor to Kay-Brunner Steel Products, Inc., Alhambra, Calif a corporation of Delaware Filed st. 12, 1960, Ser. No. 62,300 3 Claims. (Cl. 263-28) This invention relates to doors for ovens, and, more particularly, although not necessarily, to vertically movable doors for ovens used in the annealing of steel castmgs.

This application is a continuation-in-part of my copending application for United States Letters Patent Serial No. 725,336, filed March 31, 1958, entitled Door Operating Mechanism for Annealing Ovens and now abandoned.

In most foundries an overhead traveling crane is employed for lifting and transporting heavy castings from place to place therein in the treatment of the castings before they are finally finished. For instance, in annealing the castings, the crane is operated to place the castings on a car which is rolled on a track into an annealing oven at one end thereof. After annealing, the car is rolled from the other end of the oven whereupon the crane is employed to again lift the annealed castings from the car and transport them to some other point in the foundary for further treatment.

For closing opposite ends of the oven to confine the heat therein during annealing of the castings according to prior practices, doors are provided which by suitable mechanisms are vertically movable from a lowered position in which the open ends of the oven are closed, and the doors resting on the floor or ground, to an elevated position above the oven in which the oven ends are open. The door-operating mechanism as well as the doors when in open position must of necessity extend a considerable distance above the oven. Actually they project upwardly to a height such as to interfere with unobstructed movement of the overhead crane that manipulation of the crane to lower or elevate steel castings to or from a car prior and subsequent to annealing of the castings, is rendered extremely difficult without damaging the crane or the doors and their operating mechanisms.

It is a purpose of my invention to provide oven doors in conjunction with ground or floor pits in which the doors are completely received when in open position and from which pits they are elevated to closed position by operating mechanisms positioned close to the top of the oven where they offer no interference to movement of the overhead crane in the handling of castings both to and from a car.

It is also a purpose of my invention to provide simple and novel means by which either door can, when in elevated position, be moved horizontal into sealing contact with the oven so as to prevent the escape of heat from the oven and thus fully utilize such heat for annealing.

These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawings to which they relate.

Referring now to the drawings in which a preferred embodiment of the invention is illustrated.

FIGURE 1 is a side elevational view partly in section, of an annealing oven embodying a preferred form of door-operating mechanism;

FIGURE 2 is an end elevational view, partly in section, of the oven and one of the door-operating mechanisms;

FIGURE 3 is an enlarged vertical sectional view taken on line 33 of FIGURE 2;

FIGURE 4 is a vertical sectional view on a reduced scale taken on line 44 of FIGURE 3;

FIGURE 5 is a horizontal sectional view taken on line 55 of FIGURE 4;

FIGURE 6 is a fragmentary side elevational view, partly in section, of the oven and one of the door-operating mechanisms showing the door in open position;

FIGURE 7 is a view similar to FIGURE 3, but showing the door emerging from the pit and starting to lift the movable platform to open position;

FIGURE 8 is a view similar to FIGURE 7 and showing the door further raised and the platform moved to completely open position;

FIGURE 9 is an enlarged front elevational view of one of the door-latching devices; and

FIGURE 10 is a view on the same scale as FIGURE 7 and showing the latching device in side elevation and partly in section.

Referring more particularly to the drawings, in FIG- URES 1 and 2, there is shown an annealing oven 15 of the type used in foundries for annealing steel castings. This oven comprises side walls 16, a rounded top wall 17 and end walls 18, the latter being formed with aligned openings 19 of an area such that a car 20 loaded with steel castings can be rolled into the oven through one opening 19 and later rolled out of the oven through the other opening 19 following annealing. Car 20 is provided with suitable wheels 21 which ride along track rails 22 supported directly on the oven floor which is on the same level as the foundry floor exteriorly of the oven.

Doors 23 are provided for closing openings 19 after a car has been rolled into the oven, so as to confine the heat therein and thus facilitate the annealing operation. Each door 23 is vertically movable downwardly from its closed position with respect to opening 19 into concretelined pits 24, formed in the ground at both ends of the oven.

The operating mechanisms for the two doors 23 are identical and, therefore, a description of one will sufiice for both. The mechanism comprises, in the present instance, an electric motor 25 driving reduction gearing contained in a box 26 and having an output shaft 27. Through a chain-and-sprocket connection 28 the shaft 27 drives a shaft 29 which extends transversely across the top of the oven and is mounted in suitable bearings 30 and 31.

Gear box 26 and bearing 30 are supported by a bracket 32 rigidly secured to the upper end of a structure including vertical beams 33 anchored at their lower ends in the ground and connected between their ends by a transverse bracing member 34 (FIGURE 2), and at their upper ends by a second transverse bracing member 35 to which platform 32 is secured. Bearing 31 is supported on a platform 36 secured to a structure comprising vertical beams 37 anchored in the ground at their lower ends and connected by transverse bracing members 38 and 39.

As is best shown in FIGURE 2, a pair of chains 41 are trained over a pair of sprocket wheels 40 fixed to shaft 29. One end of each chain is pivotally connected as at 42 to the upper end of one of the doors 23, the other end of the chain being pivotally connected as at 43 to the upper end of a door counterweight 44. As shown, these Weights are cylindrical and slidably received in cylinders 45 located within the respective pits 24. Each pit 24 is of substantially U-form when viewed in plan, as shown in FIGURE 5, and the two cylinders 45 are secured in vertical position at opposite ends of the pit by an I-beam 46.

To facilitate rolling car 20 into and out of the oven 15 and across the. pitswhen the doors 23'are in open position, there is provided a platform P for each pit having track rails 48 and 49 aligned with tracks 50 on the floor of the foundry and with oven tracks 22.

PlatformP comprises a stationary section 51 and a movable section 52 connected together by hinges 62. Section .51 is made up of three plates 51a, 51b, and 51c to which track rails 48 are suitably secured as bywelding. Welded to the undersides of these plates are two reinforcing angle bars 53 and 54 which are Welded, in turn, to angle bars 55 and 56 extending crosswise between the rails 48. Bar 55 abuts I-beam 46, while bar 56 abuts the side of a relatively large angle bar 56a along the upper edge of one side of pit 24. Thus the platform plates are effectively braced by the bars 53 and54, and by means of the bars 55 and 56 which are in part supported in the pit 24 to allow removal of the platform as a Whole when it is found necessary to clean out the pit.

As is best shown in FIGURE 3, the outer marginal edge of the platform plates 51a, 51b and 510 repose on a supplemental pit edge 24a of concrete superimposed on the upper edge of .the pit 24, and which edge is reinforced by an angle bar 57. The straight or hinged edge of the platform rests against the upper edge of a flat bar 58 welded to the top side of I-beam 46.

Platform section 52 comprises three plates 52a, 52b, and 520, between which the track rails 49 are arranged. As is shown in FIGURE 3, the platform plates are reinforced by sectional angle bars 59 and 59a welded to the underside of the plates and to a bottom plate 60 to which therails 49 are welded. Angle bars 61 are welded to the top side of plates 52a and 52c at the side edges thereof for reinforcing the same.

To permit a car 26 to be rolled into or out of the oven door 23 is first lowered into pit 24, while platform sections 51 and 52 are in position across the top of pit 24 as-shown in FIGURE 3 with the tracks thereon interconnecting the tracks between the oven track 22 and tracks 50 on the foundry floor. However, to permit the door 23 to be first lowered into the pit, it is necessary that the section 52 be hinged to the open position shown in FIGURE 8 to expose the pit at this point.

To this end the section 52 is mounted at one edge on the confronting edge of the section 51 by a pair of hinges 62 which allow the section to be swung upwardly to the open position shown in FIGURE 8. In the horizontal or closed position of the platform section 52 as shown in FIGURE 3, its free edge rests on angle bar 63 secured to a larger angle bar 64 at a point between a supplemental pit edge 65 of concrete which covers a part of bar 64 In this closed position of the platform section v the platform-overlies and is free of contact with the upper edgeof door 23; As the door is raised. toward its closed position, it engages platform section 52 and swings this section to open position as will be more fully described hereinafter. I r

The open position of the section 52 is determined by a stop member S secured to' section 51-and of a height such that section 52 ispastppper dead center when in open position thus requiring-only a slight push with the foot to swing it back to closed position once door 23 has been lowered into the pit.

As is customary in annealing ovens, the confronting faces of side walls 16 are undercut and provided with.

coextensive depending flanges 66 (FIGURE 2) which extend into troughs 67 on the sides of the car 29 and 4 to prevent the escape of heat from the oven at the end of the car.

For moving each door 23 laterally against the respective end oven wall 18 so that the escape of heat from the oven opening 19 is reduced to a minimum, a pair of latching devices D are provided. These devices are mounted on the transverse members 34 and 38 (FIG- URE 2), respectively, and each, as shown in FIGURES 7'and 8, comprises a member 73 secured by bolts 74 to the outer side of one member 34 or 38 as the case may be, and which memberis formed with a circular opening 75 in which one end of a cylinder 76 is welded.

Fixed within the other end of the cylinder 76 is a head 77, and slidable in the cylinder is a flanged collar 78 which is fixed to a bolt or plunger 79 that is movable through the head 77 and the member 38. The outer end of the bolt 79 is operatively connected to a pair of circular earns 8 eccentrically mounted on pin 81 which extends through the cams and the bolt with its opposite endsreceived in slots 82 in parallel extensions 83 of the head 77. A block 84 is welded to and between the cams 8d, and this block is provided with a handle 85 by which the cams can be rotated.

A helical spring 86 is interposed between the head 77 and the collar 78 which acts to urge the bolt79 to the projected position shown in FIGURE 8 as permitted by the circumferential position of the cams 80. To move the bolt 79 to the retracted position shown in broken lines in FIGURE 8 the handle 85 is swung from the position shown in solid lines to the position shown in broken lines whereby, the earns are rotated about the pin 81 as a center, thereby causing the cams to engage the adjacent side of the head 77 as illustrated in broken lines to draw the bolt 79 to retracted position. During this operation the pin 81 slides outwardly in the slots 82 as illustrated in broken lines.

Under suchoperation of the bolt 79 the collar 78 is moved inwardly of the cylinder 76 to contract the spring 86 and thus hold it under tension which reacts to maintain the cams against rotation thereby holding the bolt in re tracted position. It will be understood that when the cams are rotated back to the solid-line position shown in FIGURE 8 they permit the bolt 79 to be forced to projected position under expansion of the spring 86..

In the use of my invention the two doors 23' are initially in lowered or open position within the pits 24 as shown in broken lines in FIGURE 6, while the platform sections 52 are in pit-spanning positions as shown in FIGURE 3. Thus a car 20 loaded with castings to be annealed can be rolled over the tracks of either platform P into either end of the oven to the position shown in FIGURE 1; As the car 20 is moved into the oven flanges 66 telescope into the troughs 67 causing the sand in the troughsto seal the car at its sides against the escape of heat downwardly therefrom. I

The car having been introduced into the oven the doors 23 are now separately moved to the closed position shown in FIGURE 1 through operation of each motor 25 so as to rotate each shaft 29 in a direction to rotate the sprocket wheels 40 and thu actuate the chains 41 to lift the doors to elevatedposition, and at the same time lower the counterweights 44 in the cylinders, it being understood that the weights substantially counterbalance the weight of the doors.

As illustrated in FIGURE 7, in its initial movement upwardly each door at its upper edge engages the undercontaining sand 68 to seal the joint between the flange V side of the respective platform section 52 and starts to raise the latter. With continued lifting of the door the section 52 is finally pivoted pastan upper dead-center position to the inclined open position shown in FIGURE 8 in which it engages the stop member S and there remains.

Preferably shafts 29 and connections 42 between doors 23 and chains 41 are so arranged that, in the open positions of latching devices D, doors 23 are suspended in a plane indicated by the dot and dash showing of door 23 at the right hand end of FIGURE 1. When so suspended, it is pointed out that angle iron sealing member 72 and, in fact, the entire door 23 may be lowered into pit 24 without interference with trough 69 on the end of car 20. Likewise, doors 23 may be raised to their closed positions without risks of contacting or damaging the sand sealing troughs 69 and without need for the operator having to manipulate these very heavy and very hot doors.

To bring the door into firm sealing contact with the end oven wall to prevent the escape of heat at the side and top edges of the door, the devices D are now operated to project the bolts 79 against the door which in turn moves the latter toward the oven wall. Before actual clamping of the doors to the oven wall occurs, the doors are lowered just sufliciently to submerge sealing strips 72 in the sand filling troughs 69 following which motors 25 are stopped thereby locking doors 23 at this particular height by the positive braking action provided by speed reduction devices 26. Clamps D are then fully set to press the doors in gas tight sealing contact across oven openings 19.

Once the castings have been annealed the car can be removed from one end of the oven by first releasing clamping devices D and then operating both door-operating mechanisms to lift both doors sufficiently to elevate the flanges 72 out of the troughs 69. This permits one door to swing outwardly automatically so that it can be lowered into pit 24 in the manner explained above. Once the door is so lowered the respective platform section 52 is now pushed by the foot of the operator to pit-closing position thus allowing the car to be rolled from the oven over the tracks of the platform.

In actual practice, once a car is removed from the oven, a second car loaded with castings to be annealed can be moved into the opposite end of the oven upon opening the respective door 23 when, by closing both doors and then sealing the same against the end oven walls as has been described, the annealing treatment can he proceeded with.

While the particular annealing oven herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or de sign herein shown other than as defined in the appended claims.

I claim:

1. In an industrial annealing oven of the type having a large area inlet opening in one wall thereof and provided with railway track means on the floor thereof extending outwardly through said opening and along the floor opposite said oven opening, said oven having downwardly projecting horizontal sealing flanges along the undercut opposite side walls thereof, said sealing flanges being adapted to extend into sand filled channels along the opposite sides of a car mounted on said tracks and used to carry castings to be annealed into and out of said oven, that improvement which comprises: a slab door for said oven opening, reversible power means including speed reduction means operable to raise and to lower said door between its closed position and an open position concealed in a pit located below said track means, the lower portion of said door having a downwardly projecting horizontally disposed sealing flange adapted to extend into the sand filled trough across the end of said car when present in said furnace, said door operating means including means for raising and lowering said door While spaced outwardly beyond said last mentioned sand filled trough, and means holding said door inwardly and substantially closed against said oven opening while being lowered slightly to submerge said door-supported sealing flange into said sand filled trough.

2. In an annealing oven as defined in claim 1 characterized in the provision of manually cont-rolled means for holding said door pressed closed tightly against said oven opening and wherein said speed reduction means is effective to lock said door against vertical movement so long as said motor is de-energized.

3. In an annealing oven as defined in claim 2 characterized in that said power operated means for raising and lowering said door is located closely adjacent the top of said door in the closed position thereof thereby leaving the space above said oven opening substantially unobstructed and free from interference with the operation of cranes, hoists and the like commonly used above and about annealing ovens in handling parts to be annealed.

References Cited in the file of this patent UNITED STATES PATENTS 1,504,661 Werthein et al. Aug. 12, 1924 1,606,026 G-ruendler et al. Nov. 9, 1926 1,829,710 Duach et al Oct. 27, 1931 1,867,772 Smalley July 19, 1932 2,191,438 Breeler Feb. 27, 1940 2,205,258 Hansen June 18, 1940 2,507,360 Wicks May 9, 1950 2,778,512 Strona Jan. 22, 1957 

